Abstract
Abstract: :
Purpose: Customized treatments based on wavefront sensing or video topography offer the advantage to reduce optical aberration. The increased live expectency of patients after cataract surgery and the use of refractive intraocular lenses extend the need of aberration optimization. As the customization for IOLs is technically limited, the combination of IOLs, intrastromal implants, refractive lenses and refractive surgery of the cornea is of interest. A software module to combine those procedures will be presented. Methods: The new software module is based on the data acquired with a Placido video Topometer in combination with an optical biometry system. The topography systems delivers the radius map and a surface quality map resulting from a ray tracing calculation based on that information. Adding the anterior chamber depth and the axial bulbus lengths allows the calculation of a customized IOL. As the construction of IOLs is technical limited a best fitted aspherical torical IOL is calculated. The difference to the topographic measured cornea is presented as a ablation map. This calculation is based on Ray Tracing. Results: The software module shows the cornel topography, the resulting corneal quality map, the best fitted asherical torical lens and a laser ablation profile for the cornea. For normal eyes, the ablation profile is identical with the higherally order aberrations. Corrections of decentration after LASIK for example can be divided in an astigmatic IOL and a corneal laser ablation which mainly corrects for tilt. Another option is the correction of small functional optical zones after refractive surgery using a customized bispherical IOL again in combination with a remaining laser ablation. Conclusions: The new software module allows the calculation of the combination of refractive surgery and IOL or additional lenses with the goal of aberration minimization. Especially for cataract patients this new tool allows the calculation of a best fitted aspherical IOL for the given asphericity of the cornea (oblate and prolate), particularly relevant after Refractive Corneal Surgery.
Keywords: topography • cataract • refractive surgery